I’m not just talking about the TCP/IP node architecture which interpreted censorship as damage, but all the ways since devised to tunnel through and around and inside that architecture. If you want it, you can still get outside news and dissident discussion and porn in China or Iran – heck, in the Castro family’s Cuba where infrastructure was virtually non-existent they would sneakernet in nice chunks of the Internet on hard drives and find interesting ways of distributing it. Only a totalitarian hermit kingdom like North Korea can clamp down to the extent needed.
But for your run-of-the-mill authoritarian, it’s not happening. Yes, there’s serious latency and inconvenience and sometimes required technical chops to get to the open Internet, but those who want it badly enough will find their way there. And yes, governments will push back and try to enforce their laws and try to shut things down using their own technology, but that’s an arms race they’ll lose in the end given all the free and accessible tools that build tools that build other tools that are already out there and used by hackers.
The real issue is the fact that 80%+ of Internet consumers would voluntarily limit their experience to Facebook and Twitter and other centralised (as you say, easily cowed and regulated and censored) walled gardens without a law requiring it. Even so, a huge number of those people will still want their porn, and that’s enough to create demand for holes in the system to get at it.
It’s the dessicated May’s prudish demand that Britons forego their recommended daily allowance of dirty pictures and videos that ultimately will make this wall useless for the Tories’ hidden purposes.
Authoritarians who want to benefit from the Internet are better advised to read Huxley rather than Orwell, forego the walls and look to Putin’s Russia: porn galore (with tut-tutting lip service to the concerns of the EO Church) and a lack of enforcement against gay porn from the outside, despite it being technically illegal; a constant free-flowing flood of disinformation and fake news to bury the legitimate and true, which is also allowed to flow; and centralised companies like Vkontakte and Yandex in thrall to the Kremlin in the rare cases they must prevent truly damaging information from reaching the undiscriminating masses. You don’t have to build a wall around your country’s Internet or enforce clumsy censorship when you can create an atmosphere of FUD inside a seemingly open Internet.
Satellite connections, yagis aimed at nearby offshore nodes, sneaknets if need be. Encrypted and TORed as necessary, meshed inside the country for distribution. Whatever it takes to deliver the nudie pics.